Embroidering-machine.



R. ZAHN. EMBROIDERING MACHINE. APPLICATION FILED JAN.25,1913.

1 1 1 7,743, Patented Nov. 17, 1914.

2 SHEETS-SHEBT 1.

y flop/W THE NORRIS PETERS 120.. PHOTaurMa, WASHING TON. D. C.

R. ZAHN.

EMBROIDERING MACHINE.

APPLICATION FILED JAN. 25, 1913.

1,1 17,743. Patented Nov. 17, 1914.

2 SHEETS-SHEET 2.

THE NORRIS PETERS 60., PHGTO-LITHQ. WASHING ION D. L

ENTTED dTATgES PATENT @FFTQE.

ROBERT ZAHN, OF IPLAUEN, GERMANY; ALFRED RIETZSGH ADMINISTRATOR OF SAID ZAHN, DECEASED.

EMBROID ERING-MA CHINE.

Application filed January 25, 1913.

2' '0 all whom it may concern Be it known that I, ROBERT ZAHN, a subject of the German Emperor, residing at Plauen, in Vogtland, in the Kingdom of Saxony, Germany, have invented certain new and useful Improvements in Embroidering-lilachines, of which the following is a specification.

With such shuttle embroidering machines which are equipped with thread exchanging appliances it is necessary that the group of threads not in use be put out of the way so as not to interfere with the movements of the operating needle group. One method whereby this has been hitherto accomplished is that the threads of the needle group which are out of operation are simply cut ofl. Of course, such radical method has very great disadvantages. For, although the ends of threads after they are cut off are generally fixed in position, a partial unthreading of the needles not in use during the operation of the other needle group cannot be avoided, and the rethreading of the needles consumes much time. Apart from that, the loss of time occasioned by cutt ng off the threads is also great, since this has to be done with much care in order to avoid the cutting through of the threads of the group of needles which are in operation. Another hitherto employed method of putting out of the way the threads of the group of needles not in operation, consists in that the thread tension rollers are turned so far forwardly that the threads are slackene'd and caused to hang down so as not to interfere with the threads of the operating needle group. But this method had a more serious disadvantage in that the slack threads easily become entangled and are frequently caught by the operating needles and stitched to the fabric. In consequence of this the embroidery design is spoiled.

According to this invention the threads of the needle group not in operation are neither cut off nor are their tension rollers turned or fed, but a movable thread tension mechanism for each needle group is provided, whereby the threads of the needles not in operation are released and allowed to follow the movements of the fabric frame, while the threads of the operating needles are put under the tension required for the performance of the embroidering operation.

In the present embodiment of my inven- Specification of Letters Patent.

Patented Nov. 17, 1914.

Serial No. 744,207.

tion two forms of construction are illustrated more or less diagrammatically in the accompanying drawing and so much of the embroidering machine is shown therein as is necessary for the full understanding of the operation of my device.

In the drawings similar reference letters denote corresponding parts and Figure 1 shows a side view of the embroidering mach1ne equipped with my new device and Fig. 2 is a similar view of a somewhat moditied construction.

Referring to Fig. l fI/-fl/ denotes the plane of the embroidery fabric. 1 and 2 denote the threads of the two different groups of needles fixed to the bars, 3 and 1-, which in well known manner are operated so that the needles of one group reciprocate through the spaces provided between the needles of the second group.

In the drawing the needles of bar 3 are shown in operation, and those of bar 1 out of operation or retracted from the plane of the fabric, 5 and 7 denote the respective needle spools, 6 and 8 denote the tension rollers. The spool 5 and tension roller 6 and the spool 7 and tension roller 8 are respectively carried by arms 10, 12 which are movably mounted on spindles 9 and 11 respectively and which by their own weight are adapted to tilt downwardly when the tension of their respective threads permits it. The threads for the two needle groups are conveyed from the respective spools 5 and 7 over the tension rollers 6 and 8, the rods of the secondary or small and the primary or large take up levers to their respective needle groups.

The lever 10 is provided with a nose 14: which is adapted to cooperate with a catch 13 formed on a lever 13 mounted to rock on a spindle 13 hen the needles for the thread 1 are in operation, the lever 10 is allowed to swing downwardly into the position shown, and the projection or catch 13 of the lever 13 catches the nose 14: of the lever 10 and locks the latter in that position, which at the same time comes to rest against a station ary stop 15. The spool 5 and tension roller 6, which has been swung from its dotted position 6 into the full line position, when the lever 10 becomes locked in its downwardly tilted position, operate in identically the same manner as the spool and tension roller in ordinary shuttle embroidering machines.

On the other hand, the thread 2 of the needles carried by the bar t forces the lever 12, which is not resting against the stationary stop 16, to swing to and fro in accordance as by the movement of the fabric frame the thread 2 is tensioned or slaclrened. At the transition from the operation of the needles of the needle bar 3 to those of the r-edle bar 1-, whereby the threads are .eX- cli nged, the lever 12 is permitted to tilt in the lower position so as to abut against the stationary stop 16 whereby the tension roller 8 adopts the dotted line position 8. In this position the lever 12, which, too, is provided with a nose 17, is locked by a second catch 13 of the lever 13, the same engaging the nose 1'? of the lever 12. As the catch 17 engages the finger or nose 13 it simultaneously swings the lever 13 so as to release the nose 14, and consequently the lever 10, while the lever 12 be comes locked. Now the thread 1 of the needles of the needle bar 3 following the movements of the fabric frame will cause the spool 5 and tension roller 6 to swing to and fro.

Suitably connected to the bars 3 and 1 of .the two needle groups are double-armed rocking levers 3, 1 to which are connected coupling arms 18 and 19. These coupling arms are adapted to be alternately thrown into engagement with the constantly rocking lever 20 and to actuate the lever 13, so that simultaneously with the adjustment into operative position of either one of the needle bars 3 and i, the corresponding lever or bracket which carries the tension roller and spool or bobbin is permitted to swing into operative position and is automatically locked in that position by the locking lever or arm 13, while the other bracket is automatically released from the said rocking lever or arm 13, so that the threads of the non-operating needles can follow the move ments of the fabric, rocking thereby the corresponding bracket carrying the tension roller.

In the modification, according to Fig. 2, the tension rollers 6 and S and the bobbins 5 and 7 are carried by stationary brackets or supports a and Z) respectively. In addition to the tension rollers 6 and 8, I provide tension arms 22, 23 fulcrumed at 22 23 which are actuated by springs 22, 23 and are provided with noses or projections 24:, 25 respectively. These arms also have projections 2d and 25 adapted in a certain position of their respective arms to come'to rest against stationary stops 15', 16 respectively. Gooperating with the noses 24 and 25 is the locking arm 13, which has catches 13, 13 and which is actuated by the coupling arms 18 and 19 in a similar manner as in the construction first described.

The needle threads 1 and 2 are conveyed from their respective bobbins 5 and 7 over the tension rollers 6 and 8, over the parts 20, 21 of the arms 22, 23 and over the take up rods to the respective needles.

It will be seen that when the needles carrying the thread 1 are in operation, the arm 22 of the thread tension mechanism is permitted under the action of its spring 22 to swing into the position shown so as to produce the normal tension required for the embroidering operation and that it will be auton'iatically 100 red in that position by the locking arm 13. The arm 23 of the tension mechanism for the thread 2 of the nonoperating needles will be simultaneously released from the locking arm 13 so that the threads will be allowed to follow the movement of the fabric rocking the lever 23.

What I claim and desire to secure by Letters Patent is:

1. In an embroidering machine, having alternately operating needle groups, :1 vibratory or rocking thread tension mechanism for each needle group and automatically controlled means for each tension mechanism to arrest the tension mechanisms of the operating needle group and release or unlock the tension mechanisms of the nonoperating needle group, so that the threads of the former group become normally tensioned and the threads of the latter group are permitted to follow the movement of the fabric frame.

2. In an embroidering machine, having alternately operating needle groups, a thread tension mechanism for each needle group, automatically controlled means for each tension mechanism to impart normal tension to the threads of the operating needle group and to release the tension of the threads of the non-operating needle group and automatic means for locking the said first named means in operative position.

In an embroidering machine, having alternately operating needle groups, a tension mechanism for each needle group, including a rocking member to automatically impart normal tension to the threads of the operating needle group and to release the threads of the non-operating needle group and an automatic locking mechanism for said rocking member.

4. In an embroidering machine having different needle groups for the exchange of threads, a thread tension mechanism for each needle group, yieldingly so arranged that the tension mechanism for the working needle group may adopt a fixed position while the tension mechanism for the resting needle group may be free to swing according to the movements of the fabric frame.

5. In an embroidering machine having different needle groups for the exchange of threads, a yielding thread tension mechanism for each needle group and means cooperating therewith, whereby the tension mechanism for the working needle group is allowed to adopt a certain position and to be locked therein, while the tension mechanism of the resting needle group is set free to swing according to the movements of the fabric frame.

6. In an embroidering machine having alternately operating needle groups, a vibratory or rocking thread tension mechanism for each group, an automatically operated locking mechanism for the tension mechanism and means connected to the needle groups and controlling the said locking mechanism.

7. In an embroidering machine having alternately operating needle groups, a thread tension mechanism including a vibratory or rocking member for each needle group, an

automatically operated locking mechanism for each member and means connected to the needle groups and controlling the said locking mechanism.

8. In an embroidering machine having alternately operating needle groups, a thread Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. 0." 

